1. Field of the Disclosure
The present disclosure relates to content broadcasting technology, and more particularly, to apparatuses and methods for resolving channel information inconsistencies.
2. Background
According to one aspect of the content broadcasting technology, a host such as a cable broadcast receiver may use a cable card or a Point-Of-Deployment (POD) module provided by a cable system operator. Alternatively, the cable broadcast receiver may have a built-in module that is a functional equivalent of the cable card. As such, the cable broadcast receiver, which could be an OpenCable Digital TV or a CableReady Digital TV, etc., may have a configuration that may or may not require a separate cable card. Where a cable card is required, the cable broadcast receiver may include a slot to receive the cable card. The cable card may use Personal Computer Memory Card International Association (PCMCIA) standard in order to interface with the cable broadcast receiver.
A cable broadcasting station transmits contents such as programs and channel information. The cable broadcasting station may be a cable system operator (SO) or a multiple system operator (MSO), which basically is a combination of several SOs.
The cable card inserted into the cable broadcast receiver or its equivalent receives Service Information (SI) delivered Out-Of-Band (OOB) from the cable broadcasting station. The SI information may include one or more tables that may be used by the cable broadcast receiver to create a channel map (or list). The channel map allows the cable broadcast receiver to use the channel settings set by the broadcast station. For example, an included table may be a Short-form Virtual Channel Table (SVCT). The SVCT may include a Virtual Channel Map (VCM) sub-table, a Defined Channel Map (DCM) sub-table, and an Inverse Channel Map (ICM) sub-table.
The VCM sub-table contains a virtual channel number and detailed information necessary to tune to that virtual channel number. The DCM sub-table contains all the virtual channel numbers of the cable channels that may be available to the cable broadcast receiver to be used by a user. The ICM sub-table contains the virtual channel numbers that may be mapped one-to-one to an identifier (ID) value corresponding to each channel. Usually, the DCM and VCM sub-tables are needed to configure the channel map, and the ICM sub-table is optional. In other words, the cable broadcast receiver may configure a channel map or list based on a proper combination of the received VCM and DCM sub-tables. There may be instances where the broadcasting station may transmit the VCM information and the DCM information which are inconsistent with each other. For example, the DCM information may contain channel 2 but the VCM information may not have information that defines channel 2, or vice versa. Also, the DCM information may contain channel 2, but there may be plural VCM information entries that may define channel 2 when there should be a one-to-one correspondence between the DCM information the VCM information.
Thus, when the broadcasting station transmits the DCM information and the VCM information that are inconsistent with each other, the cable broadcast receiver, which receives the information, may not be able to create a proper channel map or list. For example, a tunable channel may not exist in the channel map, or a specific channel may not work although the channel exists in the channel map.